1. Field of the Invention
This invention relates to liquid cooled brakes and, more particularly, to a fluid jacket for use in liquid cooled brakes.
2. Disclosure of Related Art
A conventional disc brake employs two sets of friction plates that are interleaved with each other to transmit a braking force. The friction plates may be made from copper to enhance frictional heat transfer within the brake. Typically, one set of plates is fixed against rotation relative to a stationary body such as a brake housing, but is axially movable relative to the stationary body. The other set of plates rotate with a rotating body such as a driven shaft, but are also axially moveable relative to the rotating body. An actuator is employed to bring the plates into engagement through which the rotating body is braked.
Braking a rotating body results in a conversion of mechanical energy to heat energy. In many instances, it is desirable to provide for effective removal of some of the heat developed from the brake structure. One method of removing heat from a disc brake is to use a liquid to cool the brake structure and transfer heat out of the brake structure. In one conventional form of a liquid cooled disc brake, one set of the friction plates define fluid jackets for circulating a cooling fluid therethrough to reduce the heat generated in the brake by the frictional engagement of the friction plates.
One conventional fluid jacket has a plurality of concentric flow passages and a radial flow passage that is in fluid communication with each of the concentric flow passages. A fluid inlet and outlet communicate with the radial flow passage. In theory, fluid is simultaneously delivered to each of the concentric passages after entering the radial flow passage from the fluid inlet. In practice, however, it has been determined that the flow of fluid is uneven within and among the concentric passages. In particular, fluid flow in the radially inner concentric passages is relatively high, while fluid flow in the radially outer concentric passages is relatively low. Effective fluid flow in the radially outer concentric passages is especially important since more heat is generated toward the radially outer portion of the friction plate which rotates at a faster speed than the radially inner portion of the plate.
The inventors herein have recognized a need for a fluid jacket for a disc brake that will minimize and/or eliminate one or more of the above-identified deficiencies.